COMP6250-Data Communications
Question 1
You work as a junior network administrator and you have been tasked by the senior network administrator to re-number the company’s internal networks.
The company is organised as follows
The address space you have been given to work with is 172.23.64.0/18.
Devise a subnetting scheme to efficiently accommodate this structure that also allows for some future growth in the number of locations, the number of departments in each location, and the number of staff within each department.
For each subnet you need to provide the following details:
• network address
• broadcast address
• netmask
• maximum number of hosts per subnet
Question 2
The role of the transport layer is two-fold:
1.To provide a communications end point so that packets delivered to a host will be given over to the correct process running on the host.
2.To potentially provide additional services or different delivery semantics than that provided by the network layer. In October 2000 SIGTRAN (the IETF Signaling Transport working group) introduced a new transport layer protocol called the Stream Control Transmission Protocol (SCTP).
3.a) What functionality does SCTP offer that is provided by neither UDP nor TCP?
b) What functionality does SCTP provide that is offered by either TCP or UDP?
c) Perform some research to find a case of an application where SCTP is utilised.
i. Briefly describe the application’s transport layer requirements.
ii. Describe how SCTP functionality fulfils these requirements. Your answer should include an explanation as to why use of this less well known transport protocol is worthwhile.
iii. If SCTP was not available, briefly explain how the application architecture could be modified so that it could work over either TCP or UDP. (Hint: think about which layer certain functionality would need to be located if using TCP or UDP instead of SCTP).
d) In spite of any perceived benefit, SCTP is not widely used. Why do you think this is?
